PORTLAND, Ore. — An Oregon congressman said Tuesday that he accepted prescription drugs from a campaign contributor last October, around the same time members of his staff complained of his erratic behavior.

Rep. David Wu told The Oregonian in a written response to a query that he had left another kind of painkiller — one prescribed by his doctor for neck pain — in Washington. He said the donor offered him an alternative, and he took two tablets.

"This was the only time that this has ever happened," Wu wrote. "I recognize that my action showed poor judgment at the time, and I sincerely regret having put my staff in a difficult position."

Earlier Tuesday, Wu said on ABC's "Good Morning America" that it was "unprofessional and inappropriate" for him to send pictures of himself wearing a tiger costume to staff members.

Wu said the photos were taken while he was "joshing around" with his children in October just before Halloween.

One photo shows Wu wearing an orange and black striped tiger outfit with pointy ears and striped mittens. Portland newspapers reported that campaign staffers pleaded with Wu to seek psychiatric help in the final week before the November election, but he refused.

The Oregonian and Willamette Week on Friday, citing interviews with a number of anonymous staff members, reported that the 55-year-old Wu was increasingly unpredictable on the campaign trial and in private last fall, and had several angry and loud outbursts.

The newspapers reported that campaign staffers were appalled by a series of e-mails sent from Wu's federally issued BlackBerry that included the photo of him in the tiger costume. But more disturbing, staffers said, were e-mails written in the voice of his adolescent children.

In an October speech to a friendly audience at a meeting of Washington County Democrats, Wu lashed out at his opponent and the media. He also talked his way past a security checkpoint to campaign for votes at the airport around that time, according to reports.

Wu on Tuesday acknowledged sending the tiger costume photos and said he has sought mental health treatment, including counseling and medication. He said in the ABC interview that he's "in a good place now," but he said he ruled out inpatient treatment because he couldn't spend time away from his family.

"Last October was not a good month. It was very stressful. I did some things, I said some things, which I sincerely regret now," Wu said.

Rep. David Wu says this photo of him dressed in a tiger outfit was taken while he was "joshing around" with his children in October just before Halloween.

The seven-term congressman assured voters he is fit to remain in office.

"I emphatically can do the job," Wu said, adding that "only time will demonstrate that to my constituents."

Wu said he was stressed from running for office while taking care of his two children as a single father and caring for his 88-year-old mother. He is separated from his wife, Michelle Wu.

"I think that mental health is a very, very important issue and people ought to feel ready, willing and able to seek it when they need it and perhaps doing this interview with you, George, will help other people feel more comfortable about addressing those issues," Wu told ABC's George Stephanopoulos.

Wu has overcome previous revelations of unusual behavior to survive seven elections. Republicans have long eyed Wu's 1st Congressional District despite a large registration advantage for Democrats, in part because of Wu's propensity to invite embarrassing news.

Wu, a Yale Law School graduate born in Taiwan, was first elected to the U.S. House in 1998. He's maintained a low profile in Congress, except for his occasional appearances in unflattering news stories.

Just weeks before the 2004 election, Wu apologized for "inexcusable behavior" after reports surfaced that a former girlfriend once claimed that he tried to sexually assault her while both were students at Stanford University in the 1970s. No charges were filed in the case, but Wu's opponent seized on the allegation to argue he was unfit for office.

Three years later, Wu's remarks on the House floor that "there are Klingons in the White House" were roundly mocked.

Seven of his staff members have left since he won re-election in November: his chief of staff, spokeswoman, three field representatives in Oregon, and two others in Washington, D.C. In addition, he lost his campaign pollster and campaign fundraiser. His campaign treasurer resigned last week, and Wu named himself treasurer.

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